In accordance with an embodiment, a measuring apparatus includes an electromagnetic wave applying unit, a detecting unit, a data processing unit, a film structure transforming unit, and a film structure measuring unit. The electromagnetic wave applying unit generates electromagnetic waves to apply it to a periodic structure of films on a substrate. The detecting unit detects the electromagnetic waves scattered or reflected by the substrate. The data processing unit calculates a surface shape of the periodic structure. The film structure transforming unit calculates a virtual film structure regarding the internal structure of the periodic structure. The film structure measuring unit calculates the thickness of each layer constituting the periodic structure by fitting a first reflectance profile by actual measurement regarding the periodic structure to a second reflectance profile obtained by a simulation using the virtual film structure to restructure the shape of the periodic structure.